For example, FIGS. 1 and 2 of Japanese unexamined patent publication No. 2000-43794 show a steering apparatus including a hydraulic pump, a steering shaft and a tilting mechanism of the foregoing type. The tilting mechanism includes a joint coupling the steering shaft to the driving shaft of the pump tiltably in a vertical plane. The tilting mechanism and the adjacent end portion of the steering shaft are covered by a bellows cover in the form of a truncated cone, from which the other portion of this shaft protrudes. The steering apparatus is mounted on or in a vessel, with the body of the hydraulic pump extending through an opening in the dashboard of the vessel.
A major portion (the portion excluding the main unit) of the hydraulic pump and the tilting mechanism extend a large amount from the dashboard toward the stern. For this reason, they interfere with steering and are unpleasant in appearance. If a portion of the hydraulic pump and the tilting mechanism extend very greatly, they are not desirable for safety when the vessel collides, turns suddenly or stops suddenly.
FIG. 4 of the foregoing publication shows another steering apparatus as an art prior to the apparatus shown in FIGS. 1 and 2 of the publication publication. This steering apparatus includes a hydraulic pump and a tilting mechanism of the foregoing type. The tilting mechanism is separate from the hydraulic pump and includes a tilting shaft. The whole of the hydraulic pump is mounted inside the dashboard of a vessel. A mounting plate is fixed to the dashboard and has a central hole, through which the driving shaft of the hydraulic pump extends. The steering shaft is coupled to the outer end of the driving shaft. The tilting mechanism is fixed to the mounting plate.
Because this hydraulic pump, the mounting plate and this tilting mechanism are separate components, the mounting operation is complex and takes time. The hydraulic pump has an oil feeding port formed inside the dashboard. If an oil feeding passage connects the oil feeding port and the outside of the dashboard, extra parts are necessary for forming the passage. If there is no such passage, it takes time and/or is troublesome to supply oil to the oil feeding port, which is positioned inside the dashboard. It is necessary to periodically bleed the air accumulating near the oil feeding port. It takes time and/or is troublesome to bleed the air accumulating near the oil feeding port, which is positioned inside the dashboard.